latex use biblatex
% In the preamble you need to use the following code:
\usepackage{biblatex}
\addbibresource{example.bib}
%citations:
\parencite[][]{author_title_date}
\cite %—the most basic one. Prints without any brackets except when using the alphabetic or numeric style when it uses square brackets;
\parencite %—prints citations in parentheses except when using the alphabetic or numeric style when it uses square brackets;
\footcite %—puts the citation in a footnote.
%Print bibliography (citations must be used in the document in order for the bibliography to be shown)
\printbibliography